Bandwidth constrained or narrowly filtered communication systems are described in U.S. Pat. No. 8,155,530 to Alic, incorporated herein by this reference.
Communication systems, and in particular those relying on bandwidth constrained equalized transport principles need to incorporate equalizers in order to mitigate either deterministic and stationary, or time varying channel impairments in order to attain a desired level of performance. As a matter of fact, the complexity of the equalizer is directly related to the length of the channel response to a single input symbol (sometimes referred to as the channel spread), resulting from the impairments. In consequence, an extended channel response may result in undesirably and even prohibitively complex solutions fail to meet the industry needs since they result in overly intricate, and, thus, highly power hungry outcomes. Currently there are a number of solutions for equalization in communication systems affected by intersymbol interference. Some of these solutions attempt to mitigate channel induced impairments acting on the known (or estimated) channel spread. However, these solutions fail to meet the needs of the industry because they transform into complex equalization structures for a given amount of intersymbol interference length. Consequences of the underlying high complexity are an increased power dissipation of the equalizer and the communication system as a whole, increased latency, and challenging implementation. Other solutions attempt to use less complex equalization structures. However, these solutions are similarly unable to meet the needs of the industry because of the inappropriate performance associated with the latter equalizers.
Low complexity equalization is a critical practical concern in communication systems realization. The said property translates to lower receiver and system overall power dissipation, lower latency and complexity. Consequently, there currently exists a clear need in the industry for a reduced complexity equalizers, in particular related to bandwidth constrained equalized transport systems. It would, thus, be desirable to have a composition (i.e. an equalizer) that is capable of providing a superior mitigation of the intersymbol interference, and, thus, performance of communication systems, while maintaining a lower complexity, and low power dissipation which/that can be used to both user and system-provider benefit. Furthermore, it would also be desirable to have a composition that operates with low latency. Still further, it would be desirable to have a compound with good performance and a low complexity. Therefore, there currently exists a need in the industry for a composition that performs adequate equalization of the channel response, while maintaining low complexity of the underlying equalizer structure.